# Image Capture


Here’s a guide on capturing video of a planet for use of lucky imaging:

## Software
- Rain City Astro is hard at work developing a image capture function for Planet Stacker X, in the mean time we recommend [FireCapture](https://www.firecapture.de) for image capture as they have a native MacOS app and support a wide range of cameras and capture options. 

## Equipment 

- Telescope: Use a telescope with sufficient aperture and focal length. For planetary imaging, you will want a focal length of at least 2000mm and a focal ratio of at least f/15 in order to provide a large image scale, which is crucial for capturing planetary detail. 
- Camera: A high-frame-rate, low-noise camera (like a planetary or monochrome camera) is ideal. These cameras are capable of capturing fine details quickly, which is essential in moments of good seeing.
- Barlow Lens (Optional): Consider a 2x or 3x Barlow lens to increase your telescope’s effective focal length, which is helpful for achieving a larger image scale.
- Mount: Use a stable, tracking mount to keep the planet centered as it moves. You can use either an equatorial or an altazimuth mount in planetary imaging.

## Conditions
- Clear Skies and Good Seeing: Capture when the sky is clear and seeing conditions are stable (no twinkling stars). Look for nights with low turbulence and low wind.
- Planetary Altitude: Try to capture planets when they’re high in the sky (above 30°). Atmospheric turbulence is less at higher altitudes, providing sharper images.
- Cool Down the Telescope: Allow your telescope to acclimate to outdoor temperatures to avoid heat distortion. This can take up to an hour or more for larger scopes.
- Collimate the Telescope: If you are using a telescope that allows it, esnure your telescope is precisely collimated before each imaging session. This is crucial to being able to achieve precise focus and capture fine detail.

## Camera Settings
- Frame Rate: Aim for a high frame rate (30–200 fps) to capture many frames quickly. Higher frame rates increase the odds of capturing moments of steady atmospheric seeing.
- Exposure Time: Use short exposure times (5–20 ms) to "freeze" the turbulence. Balancing exposure and gain is key to preventing either underexposure or over-saturation.
- Gain: Set gain high enough to keep exposure times short but low enough to avoid excessive noise. A higher gain setting with shorter exposures generally yields better results.
- ROI (Region of Interest): Crop the sensor output around the planet to reduce file size and increase frame rate.

## Focusing
- Achieve Precise Focus: Use a Bahtinov mask on a bright star nearby to help achieve focus. If unavailable, adjust focus directly on the planet, looking for surface details or features.
- Check Often: Even slight shifts in focus can affect detail; check focus periodically as conditions and temperature can shift during the session.

## Capture Duration
- Optimal Duration: Capture video for 1-3 minutes for Jupiter, 3-6 minutes for Saturn, and from 5-10 minutes for Mars, Venus, and Uranaus. This is to avoid blur from the planets natural rotation.
